I just went out to the garage and tried to record the ticking with my digital camera. I posted the vid on U-tube.
YouTube - Hemi cabin tick
The vid is about 1 minute long but the ticking can only be barely heard during the 18-20 and 26-30 second portion of the vid. Ignore the radio/outerspace noises, I think my camera was making these strange sounds.
I believe the sound is coming from the speakers.
I tried different recordings and couldn't pick up the ticking until I placed the camera over the driver side speaker.